Cutter head of dry-shaving apparatus



Dec.

w. L. L. VIVIE 2,816,358

CUTTER HEAD OF DRY-SHAVING APPARATUS Filed July 22, 1953 INVENTOR. WILHELMUS LAMBERTUS LEONARDUS VIVIE AGENT United States PatentD."

CUTTER HEAD OF DRY-SHAVING APPARATUS Wilhelmus Lambertus Leonardus Vivie, Eindhoven, Netherlands, assignor, by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application July 22, 1953, Serial No. 369,602

1 Claim. (Cl. 30-43) This invention relates to a cutter and cutting plate construction and arrangement for a dry-shaving apparatus. This application is a continuation-in-part application of my co-pending application Serial No. 680,872, filed July 2, 1946, now abandoned.

In the usual constructions of a cutter head of a dryshaving device the cutter head is secured at the outer edge, for example by means of a nut, to a supporting body which generally is integral with the housing or the frame of the apparatus.

The invention is based on recognition of the fact that the central part of the cutting plate being highly flexible due to the minute thickness thereof is frequently liable to oscillations which detrimentally affect the cutter action and in addition may considerably shorten the life of the cutting plate on account of fatigue phenomena of the material. The oscillations are generally originated by the drive means and, particularly in systems comprising a cutter adapted to rotate about a spindle, may acquire a considerable amplitude in some cases due to resonance phenomena. Thus, for example, in a device freely rotating in the air and having a well-known type of cutting plate comprising radial slits and a central re-entrant part an amplitude of 17 was established. In addition, due to the pressure on the skin which is continually varying, the cutting plate is liable to sag even more heavily.

According to the invention, the said disadvantages are obviated in that in a cutter head comprising a cutting plate and a supporting member for the outer edge thereof the central part of the cutting plate is also supported on the lower side in a direction normal to the plane of the cutting plate, or in some cases is secured to the support. Obviously this support and the supporting member for the outer edge form a rigid unitary piece so that the center of the cutting plate is immovably secured in place.

In addition, this arrangement of rigidly supporting the central portion of the cutting plate permits of the active apertured part of the cutting plate being given larger radial dimensions than has heretofore been used.

It is known to support the cutting plate of a dry-shaving device merely at the central part by securing it in position on a stud which across the hollow shaft of the drive bears on a rigidly mounted part of the frame or the housing of the apparatus. In this case, however, the outer edge of the cutter plate is fitted with a rim of teeth in which the ends of the teeth are free to move so that a smarting influence is exercised on the skin and the cutting plate has to be constructed so as to be thicker for considerations of mechanical strength and the rim teeth formed so as to be shorter than is generally desirable in connection with a satisfactory shaving operation. The invention does therefore not relate to a construction of this kind since the central support of the cutting plate as such is not essential on account of the support already existing at the outer edge but only serves for anchoring the cutting plate.

According to a further feature of the invention all 2,816,358 Patented. Dec. 1'1, 19,57

ice

in one plane. Even in wholesale production in mountin the cutting plate this ensures asirnplemanneran accurate support or attachment without warping or flexing of the cutting plate.

In order that the invention may be clearly understood and readily carried into effect it will now be described more fully with reference to the accompanying drawing in which one embodiment of the invention is diagrammatically shown.

According to the invention, the cutting plate 1 is supported and secured both at the outer edge 2 and at the central part 3 on the lower side in a direction normal to the plane of the cutting plate, this being effected re spectively by means of the edge 4 of the housing 5 and a stud 6 which is fast in the bottom of the housing and comprises a supporting surface 7, the stud 6 being assumed as a bearing for the hollow shaft 12.

The cutting plate is secured in position with the help of a nut 8 and a small screw 9 so that all the forces that occur in an axial direction are absorbed.

As may be seen from the figure, the supporting surfaces 4 and 7 are caused to be located in one plane, for example by cutting, so that exactly fitting surfaces are safeguarded.

The invention is of particular importance with constructions in which use is made of a cutting plate comprising a central re-entrant part 10 and radially or taugentially directed slits 11 of relatively large length since this construction has been found to be highly sensitive to the said vibration.

As seen in the drawing the cutter 21 is urged against the cutting plate 1. The hollow shaft 12 connected to a motor (not shown) has an enlarged end thereof provided with two ribs 13. An annular recess 14 is cut in ribs 13. A helical spring 15 surrounds stud 6 having one end in the recess 14 and the other end urged against a member 16. Member 16 comprises a cylindrical part 17 having two opposed grooves 18. Ribs 13 are positioned in grooves 18. Member 16 is therefore freely movable in an axial direction relative to the motor shaft 12. The rotation of motor shaft 12 will cause member 16 to rotate. Member 16 is further provided with two pins 19 and two projections 20. The cutter 21 has two holes 22 into which pins 19 project. Thus, when the cutter 21 is urged against the cutting plate 1 by the spring 15 through the member 16, the projections 20 are urged against the cutter 21 thereby transmitting the rotational movement of the motor shaft 12 to the cutter 21 and at the same time maintaining the cutting plate 1 substantially free from oscillations or vibrations.

While I have shown and described the preferred embodiment of my invention, it will be understood that the latter may be embodied otherwise than as herein specifically illustrated or described and that in the illustrated embodiment certain changes in the details of construction and in the arrangement of parts may be made without departing from the underlying idea or principle of the invention within the scope of the appended claim.

What I claim is:

Dry-shaving apparatus comprising a cup-like housing member, a bearing shaft member secured to the bottom portion of said housing member so as to be centrally positioned therein, a cutting plate member having an outer portion thereof coupled to the wall of said housing member and a central re-entrant portion, means mounting said re-entrant portion rigidly on the top portion of said shaft member, a cutter, an intermediate member coupled to said cutter and provided with at least one slot References Cited in the file of this patent parted to said cutter, and resilient means positioned be- 6 2,282,539

tween said hollow shaft driving means and said intermediate member to thereby resiliently urge said cutter against a portion of said cutting-plate member.

UNITED STATES PATENTS Testi Nov. 1, 1938 Bahr May 12, 1942 FOREIGN PATENTS Great Britain Apr. 22, 1941 all at 

